Robert Mugabe's disregard for democracy and human rights is shared to varying degrees by many of the leaders who have been urged to condemn him today at the African Union summit in Egypt. Publicly defenestrating Zimbabwe's self-declared president might create an uncomfortable precedent for them – and for this reason among others, is thus unlikely to happen.

Hosni Mubarak, veteran host of the meeting of the 53 AU countries, may be said to have set the standard to which others have fallen. He has been repeatedly returned as president with over 90% of the vote in effectively uncontested elections. Egypt's biggest political party, the Muslim Brotherhood, is banned.

South Africa's leader, Thabo Mbeki, is widely seen as chief enabler and perpetuator of Mugabe's misrule through his misjudged pursuit of a supine "quiet diplomacy". One direct consequence was the recent outburst of xenophobic violence against Zimbabwean refugees in South Africa. Under Mbeki, the "rainbow nation" has moved inexorably towards one-party rule.

Other aspiring African regional powers, such as Nigeria, exhibit similar leadership failings. International and domestic observers reported massive fraud, including vote-rigging and political violence, during presidential, parliamentary and state polls apparently won hands down last year by the People's Democratic party.

The US state department's 2007 country report on Nigeria said: "The government's human rights record remained poor and government officials at all levels continued to commit serious abuses". Extrajudicial killings and torture by the security forces and "the abridgement of citizens' rights to change their government" were among problems cited.

Notorious human rights abuses in Sudan, Congo and Somalia tend to deflect attention away from the unpleasant excesses of more obscure regimes such as those in Chad and Eritrea. A former role model, President Yoweri Museveni of Uganda, has meanwhile proved disappointingly incapable of embracing democratic transition. More than 1,500 dead in the wake of Kenya's rigged polls last winter testify to a more general fragility affecting democratic institutions across Africa.

It would be foolish to write off a whole continent's political leaders because of the venality and corruption of a few. Though by no means problem-free, many countries are making headway. Botswana and Zambia, outspoken on the Mugabe issue, are among them; so, too, is Senegal. In Ghana, Amnesty International approvingly reports the continued payment of reparations to victims of human rights violations committed under previous governments.

Ethiopia, one of the poorest countries on earth, has made considerable progress in lifting itself up, politically and economically. Its prime minister, Meles Zenawi, argues it is in any case irrational and unfair to expect the instant attainment of Westminster-style standards of governance from struggling developing nations emerging, in many cases, from decades of colonial exploitation, dictatorship, war and famine.

Organisations such as Human Rights Watch respond that the AU should uphold its own 2007 Charter on Democracy, Elections and Governance that proscribes, for example, "illegal means of maintaining power" akin to those employed by Zanu-PF.

All the same, and whatever they may think in private, few African leaders, progressive or otherwise, appear ready to publicly back western efforts, led by Britain and the US, to turn Mugabe into an international pariah. Support for withdrawal of official recognition, tougher sanctions, and suspension of Zimbabwe from the AU or even the UN appears very limited.

Some leaders profess residual respect for Mugabe as an erstwhile liberation hero. Most are reluctant to be seen to be following behind George Bush and former European colonial masters. And a few may have been influenced by Mugabe's crude threat to turn the tables on them if there is any summit finger-pointing.

Mugabe "was prepared to face any of his AU counterparts disparaging Zimbabwe's electoral conduct because some of their countries had a worse record," the state-controlled Herald newspaper in Harare reported today.

The unprecedented criticism levelled at the regime by its southern African neighbours is thus unlikely to translate into harsh punishment or intervention, as demanded by the likes of Desmond Tutu. Mugabe's unhindered admission to the Sharm el-Sheikh summit and the conciliatory comments of Jean Ping, AU commission chairman, among others, suggest a loose agreement that Zanu-PF enter into talks with the opposition Movement for Democratic Change is all that will be required of Mugabe at the summit.

Zimbabwe's friends and neighbours should "do everything in (their) power to help the Zimbabwe parties to work together in the supreme interests of their country," Ping said. That vague formula leaves recently floated ideas of a government of national unity, other power-sharing arrangements, or a transitional government (as belatedly proposed by South Africa) wholly up in the air.

This latest crisis, the worst since he took power in 1980, has undoubtedly weakened Mugabe. He is more reliant now on key political cronies and security chiefs. His reputation among his African peers is much damaged. The country is economically on its knees.

It may well be that Zimbabwe has finally reached the beginning of the end of the "old Bob" era. But the wait for his final departure, once the global fuss dies down, could still be a long one.